package com.scut.fy.common.web.util;

import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.web.server.ServerWebExchange;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Optional;

/**
 *
 * @author YF
 */
public class IpUtil {
    public static String getIpAddr(ServerWebExchange exchange) {
        String ipAddress = "";
        ServerHttpRequest request = exchange.getRequest();
        try {
            ipAddress = request.getQueryParams().getFirst("x-forwarded-for");
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getQueryParams().getFirst("Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getQueryParams().getFirst("WL-Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = Optional.ofNullable(request.getRemoteAddress())
                .map(address -> address.getAddress().getHostAddress())
                .orElse("");
                if ("127.0.0.1".equals(ipAddress)) {
                    // 根据网卡取本机配置的IP
                    InetAddress inet = null;
                    try {
                        inet = InetAddress.getLocalHost();
                    } catch (UnknownHostException e) {
                        e.printStackTrace();
                    }
                    ipAddress = inet.getHostAddress();
                }
            }
            // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
            if (ipAddress != null && ipAddress.length() > 15) {
                // "***.***.***.***".length()
                // = 15
                if (ipAddress.indexOf(",") > 0) {
                    ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
                }
            }
        } catch (Exception e) {
            ipAddress = "";
        }

        return ipAddress;
    }
}
